In the US the big problem would be controlling tax loopholes at the higher brackets.  That problem is essentially insoluble with the current system of campaign finance, as the average citizen only gets to vote for their representatives; representatives actually work for the large contributors.  Fix that and things might improve.

The other big obstacle is the degree to which the neo-classical mythos has been written into the brains of so many of our populations.  Given over 30 years of repetition and conditioning and the extent of biblical world views I wouldn't be surprised if >50% actually think that "The Invisible Hand" is "The Left Hand of God."  Half or more of such folks would rather believe that the present financial crisis is all an evil plot of the Democrats, even if the Democrats didn't have a black man as their presidential candidate.

Perhaps this is best attacked through humor.  In the '30s and '40s labor organizers added alternate lyrics to old religious standbys such as May the Circle be Unbroken:

May the Circle be unbroken
In the Great Bye and Bye
There is a better world awaiting
In the sky, Lord, in the sky

This was appended with:

There'll be Pie in the Sky
Bye and Bye! It's a Lie!

Followed by a "consciousness raising" discussion.

"It is not necessary to have hope in order to persevere."